<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>边框</title>
  <style>
    #d1{
      width: 400px;
      height: 400px;
      border-width: 20px;
      border-color: blue;
      background-color: skyblue;
      border-left-width:20px ;
      border-top-width:20px ;
      border-top-style: solid;

      border-right-style: solid;
      border-top-color: red;
      /* 复合属性 */
      border: solid yellow 10px;
      border-style: dotted;
      border-left: solid pink 30px;

    }
  </style>
</head>
<body>
  <div id ="d1">你好啊</div>
  
</body>
</html>